RichP1023

Hi All! Picked up a 2000 GT Convertible a few weeks back. Needed a car so I sold my Yamaha Warrior bike and picked up the GT. When I was younger and just out of HS I really wanted a Mustang. I did get a Ford at the time, but it was a Taurus...

Interior needs some work, but the exterior is in pretty good shape. Engine is strong, but I think the Auto Trans needs to be replaced soon. Just got a Bama tuner in the mail today and if I didn't work late I would have been out there tuning it already.

88 orangepeel notch

That cars so hot it burned the flower bed !!!

Welcome

RichP1023

Haha nice... I can thank the polar vortex for that one.

Was able to apply the Bama Performance Tune today and what a difference! Still having speedo issues, but I'll figure that out.

AMWill

The car's exterior looks like it's in great shape. Was it recently repainted? I know the front Roush bumper most have been, but maybe the previous owner painted the whole car?

Glad you're enjoying the Bama tune too! Custom tunes especially help automatic transmission shift points. As the factory settings are brutal IMO.

What issues are you having with the speedo? Is it reading too high or too low or just not working correctly at all?

Shane

RichP1023

Thanks! The exterior was really the one thing I didn't need to worry about other than getting a new hood scoop (previous one was taken off and the holes are still there)... Until my brother in law hit my rear quarter with his jeep. Not a big hit, but enough that I'll have to spend a few bucks fixing it. It may have been recently painted with the Roush kit, not sure. I do know that it was in an accident about a year and a half ago, so it's quite possible it was done then.

The speedo has been off since I got the car. The speedo speed is ~10 mph over the ECU Speed which was about 10% off the GPS speed. The only thing I could come up with was that the car was tuned with higher gears at one point. Then the gears returned stock. Once I did the Bama tune it's closer to the GPS speed but still off. When I get a chance I'm going to put the speedo in test mode, look at the digital speed and compare it to the GPS speed. This will tell me if the ECU is still off or if it is just a speedo problem.

96t-bird

Welcome. Glad you got the speedo problem going in the right direction.

sdstang

Welcome to the forum.

RichP1023

Going in the right direction, but definitely not there yet. Went out at lunch and used the digital speedo. Still about 8-10 mph higher than the GPS speed. I did find out that the transmission was replaced at one point. Not sure if that is a factor here.

Taking the speedomoter itself out of the equation, I'm not sure where to go next as far as the ECU speed being off.

I did receive the following speedometer codes when i went to turn on the digital speedo, but not sure any of them have anything to do with this issue:
dtcd043 - SCP Invalid or missing data for Traction Control
dtcd262 - Missing SCP message
dtc5284 - Oil Pressure Switch Failure

AMWill

Are you positive the factory gears are installed in the rear? Have you tried the "driveshaft test" by having a buddy spin one tire a full rotation while you watch a mark on the DS? This is the easiest way to roughly tell what gears are installed in the rear.

I have a feeling this is your issue. Since your speedo is just a few MPH off and not moving slow or any the sort.

Shane

RichP1023

I've been putting off the driveshaft test, but think I'll have to do it this weekend. That being said, it was my understanding that if the car was tuned for stock gears, if a higher gear is put in, the speedomoter would read slower than the GPS speed. I'm having the opposite problem. I will do this though so I know for sure what the gears are.

BTW - Thank you all for the help!